When assigned to summarize something, it is often as a means of testing a student's understanding of the original material. Hence, one thing you want to be sure to do in a summary is restate the main purpose of the original. Ask yourself, what is the author's main point, main idea, or thesis? These questions will especially be important for a work of non-fiction like A Short Life of Jonathan Edwards. Once you've identified the main purpose, you next want to identify the main parts of the argument. Looking at the table of contents can help you easily see how the author has broken up the argument, plus the titles of the chapters help you quickly identify any one important thing the author wants to argue in any given chapter, and that one thing will directly tie back up to the author's main point or thesis. As you write your summary, start out with writing one to two sentences to express the central idea then one to two sentences to express each main point of his argument as divided by the chapters. Then, depending on how long your summary should be, continue filling in important details from that general outline. As we are limited in space, below are a few ideas to help get you started.
George Marsden's main point is clearly stated in his opening chapter. His purpose is to compare Jonathan Edwards' and Benjamin Franklin's reactions to the demise of the Calvinism of the Puritans and the rise of modern British society with the intention of showing us how both their reactions helped shape America. One of his main arguments is to show that it was Edwards' own reaction that helped establish the dominantly religious America as we know it today. As Marsden phrases it:
If we think of the Puritans as one of America's first immigrant communities, then the opposing reactions of Edwards and Franklin to the dramatic transitions of their era becomes the prototype of a classic American story. (p. 3)
One main point in his argument is to direct the reader's attention to the fact that there were actually two revolutions happening at the time as the American Revolution. The most commonly spoken of revolution was of course the political revolution the colonists began against the British, but at the same time, there was also a spiritual revolution taking place known as the Great Awakening. He further asserts that it is due to this spiritual revolution that America is what it is today, a paradoxical nation that is both "one of the most industrialized, technologically advanced modern nations" that is even very secular, but also "remarkably religious" (p. 135). The U.S. is more religious than England or any country in Europe. He even asserts that "probably more people regularly attend church today than they did in the colonial era," and it is due to the Great Awakening (p. 135).
Marsden further points out that it was Edwards who was one of the major founders of the Great Awakening, just like Thomas Jefferson was one of the great founders of the American Revolution and of our nation. The American Revolution ignited, not just a revolution against England, but even against its church with all of its routines. The Revolution gave new life to the Protestant idea that mankind's salvation does not come from any church authority but "rather directly through Christ's saving work to each individual" (p. 134). Hence, among the theologies that were taught during the Revolution as a part of the Great Awakening was the idea that mankind can have a personal relationship with God, and it was particularly Edwards who pushed this theology, the same theology upon which most American Protestant churches are founded upon that make America one of the most equally modernized and religious countries in the world. Edwards specifically taught that the universe is not an impersonal object but rather a beautiful expression of God's love. He further taught that it is through the Holy Spirit sinners are transformed, and after being transformed, what becomes most important is loving that which God loves. This idea that one can have a personal, transformational relationship with God sharply contrasted with the ideas of the founding fathers like Franklin and Jefferson who were deists. Deists, as a product of the Enlightenment, saw the universe as nothing but an impersonal, "intricate machine" running on Newtonian laws and saw God as nothing but a "cosmic watchmaker" who set the machine in motion and then let it run without his interference. Hence, Edwards' theology not only greatly contrasted with the theology of his day but also revolutionized understandings about God and the universe, and it is these same understandings that have made America the religious country it is today.
Hence, we see through Marsden that there were actually two revolutions going on at the time as the American Revolution and both revolutions played an equal role in creating the America we know today. To continue your summary, you'll next want to learn exactly how Marsden compares Edwards and Franklin. For example, how did Franklin react to the Great Awakening that was different Edwards' reaction, and how did this impact the creation of America? Once you have that information, you'll be able to see why Marsden sees both Edwards and Franklin as being equally important in the creation of America as well as how Edwards influenced the religious aspect of America, and it is the creation of America that is Marsden's central point.